The term for various forms of economic system involving public or worker ownership and administration of the means of production and allocation of resources. In theory, all citizens should have equal access to resources and compensation based on the amount of labor they contribute to the society.

Though there have been many different attempts to put socialism into practice, including the Yugoslavian, Hungarian, German, and Chinese communist governments who all tried to introduce some free-market exchange and free-price system (called “market socialism”), the most prominent form of socialism in the twentieth century was the Soviet model of economic development in Russia, in which the state owned all the means of production and attempted to plan all economic policy

The photo at right, taken at the second Party Congress in 1919, shows Bolshevik leaders Leon Trotsky, Vladimir Lenin, and Lev Kamenev.